The present invention relates to novel sialosylceramides and a production method thereof.
The glycolipid of mammalian cells comprises a lipid structure expressed as a ceramide in which a fatty acid is amido-bonded to sphinogosine of a long chain amino alcohol and to which sugars such as glucose, galactose, N-acetylglucosamine, N-acethylgalactosamine, fucose, and sialic acid are bonded through glicosidic linkage in various combinations, and belongs to the category of so-called sphingoglycolipids. In particular, the glycolipid having sialic acid is called ganglioside.
Most of these compounds are generally located in the outer molecular layer of the two molecular layers of cell membrane and it has been thought from recent investigations that the compounds play an important role in the function as a reception and response receptor of recognition and information, differentiation, proliferation, malignant change, or behavior in cells.
However, the function of ganglioside-based glycolipid as a component of cell membrane has not been sufficiently elucidated and it is difficult to isolate ganglioside from an organism and purify it.
Although precision synthesis of GM.sub.3 (GM: ganglioside monosialo) and GM.sub.4 has been successfully achieved, the synthesis of an unnatural compound (GM.sub.5) of the present invention which has a similar structure to that of the above compounds is necessary and indispensable to the elucidation of the function of the ganglioside-based glycolipid as a component of cell membrane.